The present invention relates to a sliding compound miter saw.
EP2689878 describes a sliding compound miter saw. Such saws comprise a cutting unit movably mounted on a base assembly. An electric motor is mounted in the cutting unit which is capable of rotationally driving as cutting blade mounted on a spindle which projects from the cutting unit. A sliding compound miter saw can perform chop cuts, bevel cuts, miter cuts and sliding cuts on work pieces located on the base assembly.
Referring to
Rotatable table 100 may be rotatably mounted on the base 6 between the two platforms 12. Preferably, the top surface 102 of rotatable table 100 is flat and lies flush with the flat top surfaces 104 of the two platforms 12. The combined surfaces 102, 104 of the platforms 12 and rotatable table 100 preferably form a work surface.
An extension arm 106 may be rigidly attached to the rotatable table 100 and extends forwardly. The rotatable table 100 and extension arm 106 can pivot about a vertical axis through a range of angular positions. The angular movement may be restricted by the extension arm 106 engaging with one or other of the sides 108 of the platforms 12. A locking lever 120 can be used to lock the rotatable table 100 and extension arm 106 in desired angular positions. A scale 122 (shown in
Referring to
Each handle 10 preferably has a recess 620 which has corresponding dimensions to those of the ledges 600. When attaching the handles 10 to the base 6, each handle 10 is lowered (along the direction of Arrow A) onto the base 6 from above the base 6. When each handle 10 is mounted on the base 6, each ledge 600 locates within the recess 620 of each handle 10. Two apertures 606 are preferably formed through each handle 10 in corresponding positions to the threaded apertures 602 in the base 6. Bolts 608 may be passed through the apertures 606 and screwed into the threaded apertures 602 of the posts 604 to secure each handle 10 to the base 6. The top surfaces 610 of each handle 10 are preferably flat and lie flush with the top surfaces 102, 104 of the two platforms 12 and rotatable table 100. The surfaces 610 of the handle 10 therefore extend the work surface formed by the combined surfaces 610, 102, 104 of the platforms 12 and rotatable table 100. As such, the handles 10 can remain attached while the saw is being used. The handles further help an operator in manoeuvring the saw between different locations.
A mount 27 may be pivotally mounted on the rear of the rotatable table 100 to form a bevel joint. The mount 27 can pivot about a horizontal axis relative to the rotatable table 100 to enable the saw to perform bevel cuts. Two guide rods 200 are pivotally attached to the mount 27 via a pivot joint which is described in more detail below. A cutting unit 50 is preferably slideably mounted on the two guide rods 200.
The external housing of the cutting unit 50 is preferably constructed from five clam shells 300, 302, 304, 306, 307. The first clam shell 300 forms a motor housing in which is mounted an electric motor (not shown). The first clam shell 300 may be attached to the fifth clam shell 307 using bolts. The fifth clam shell 307 preferably forms a motor mount for the electric motor. The fifth clam shell 307 preferably supports the guide mechanism for the two guide rods 200 and supports the cutting unit 50 on the guide rods 200 and which is described in more detail below. The fifth clam shell 307 may be made from aluminum which is unlike the four other clam shells 300, 302, 304, 306 which are preferably made from plastic.
The fifth clam shell 307 may be attached to the second clam shell 302 using bolts. The second and third clam shells 302, 304 are preferably attached to each other using bolts and which, in addition to the fifth clam shell 307, form a guide rod support housing, in which the two guide rods 200 are slideably mounted. The second and third clam shells 302, 304 may also form half of the fixed blade guard, which preferably surrounds the top section of a cutting blade 124 which is mounted on an output spindle 500 of the motor. The fourth clam shell 306 may be attached to the third clam shell 304 and preferably forms the second half of the fixed blade guard.
The pivot joint preferably enables the two rods 200 and the cutting unit 50 to pivot about an axis 202 relative to the mount 27 to enable the two rods 200 and the cutting unit 50 to pivot away from or towards the rotatable table 100 and extension arm 106. This enables the saw to perform chop cuts. A spring 204, which forms part of the pivot joint, biases the mount 27 and guide rods 200 to their highest position. A handle 114 may be attached to the front of the cutting unit 50 by which a user manoeuvres the cutting unit 50 relative to the base structure. The mount 27 automatically locks in its uppermost pivotal position by a latch mechanism (not shown). A pivotal lever 116 is preferably mounted on the handle 114 by which an operator can release the latch mechanism. A switch 118 may also be mounted on the handle 114, the depression of which activates the electric motor.
A fixed fence 16 is rigidly attached on top of the two platforms 12 of the base 6 at the rear of the platforms 12. The fence 16 extends across the rotatable table 100 but does not interfere with its rotational movement.
The pivot joint will now be described in more detail with reference to
A base 222 may be rigidly attached to the end of the two guide rods 200 to hold the two guide rods 200 in position. The base 222 preferably comprises two metal clam shells 224, 226 which are clamped around the end of the guide rods 200 and secured to each other and the guide rods using bolts 228.
One of the clam shells 224 may comprise a circular wall 230 which connects to a circular base 232 formed on the side of the clam shell 224. The size and dimensions of the circular wall 230 are such that it is capable of mating with the groove 214 of the cup shaped section 206 as best seen in
An elongate tube 234 preferably extends from the clam shell 224 at the center of the circular wall 230 and in parallel to the circular wall 230. When the circular wall 230 is mated with the groove 214 of the cup shaped section 206, the elongate tube 234 preferably extends into the tubular passage 208 as best seen in
The pivot joint may comprise the spring 204 which has a central coiled section 234 and two straight ends 236, 238.
When the pivot joint assembled, the circular wall 230 is preferably mated with the groove 214 of the cup shaped section 206. The spring 204 is located inside of the tubular passage 208 with the coiled section surrounding the elongate tube 234. One of the straight ends 236 preferably locates within a recess 240 formed in the end wall 212 of the cup shaped section 206 to attach it to the cup shaped section 206. The other straight end 238 preferably locates in a second recess 242 formed in the clam shell 224 inside of the circular base 232 to attach it to the clam shell 224. A bolt 244 may be passed through the aperture 220 in the end wall 212 and through the elongate tube 234. The head 246 of the bolt 244 preferably locates against the outside of the end wall 212. A nut 248 and a washer 250 are preferably screwed on the free end the bolt 244 and abut against the end of the elongate tube as best seen in
The base 222 can pivot on the mount 27 about axis 202 by the circular wall 230 rotating around the groove 214 while remaining mated to it. As the base 222 pivots on the mount 27, the cup shape section 206 and/or the circular wall 230 rotates around the bolt 244. The base 222 is preferably pivotally supported on the mount 27 by the engagement of circular wall 230 and the groove 214. As the circular wall 230 rotates within the groove 214, one straight end 236 of the spring 204 rotates relative to the other end 238, storing a spring force in the coiled section 234. The spring 204 applies a biasing force between the cup shaped section 206 and the clam shell 224. The spring 204 is arranged to urge the two guide rods 200 to urge them to point upwardly and move the cutting unit 50 to its highest position. The angular movement of the base 222 on the mount 27 is limited by a projection 250 on the base 222 travelling between two end stops 252, 254 as the base 222 pivots on the mount 27. The spring 204 remains under tension regardless of the relative angular positions of the base 222 and the mount 27.
The guide mechanism for the guide rods 200 will now be described. Two brackets 502 may be formed in the top section of the fifth clam shell 307. Each bracket 502 may have straight bracket passages 504 which are tubular formed through them. The two bracket passages 504 are preferably of equal dimensions. Both bracket passages 504 may be circular in cross section along the length of the bracket passages 504 and have a constant diameter along the length of the bracket passages 504. The two bracket passages 504 are preferably aligned so that their longitudinal axes 512 are co-axial. A slide bearing 506 is preferably press fitted into and held within each of the bracket passages 504. Slide bearings are well known in the art and therefore their particular construction is not discussed in any detail. However, any suitable commercial slide bearing can be utilised.
A third bracket 508 may be formed in the lower section of the fifth clam shell 307. Third bracket 508 preferably has a straight third bracket passage 510, which is preferably tubular, formed through it. The third bracket 508, together with the third bracket passage 510, may extend the full length of the fifth clam shell 307. The third bracket passage 510 is preferably circular in cross-section along the length of the third bracket passage 504 and has a constant diameter along the length of the third bracket passage 510. The longitudinal axis 514 of the third bracket passage 510 is preferably parallel to the longitudinal axes 512 of the first two bracket passages 502.
Both guide rods 200 are preferably circular in cross section and of equal uniform diameter along their lengths. The size of the outer diameter of the two guide rods 200 preferably corresponds to that of the inner diameter of the slide bearings 506 so that the upper rod 200 locates in a congruent manner within and is capable of sliding within the two slide bearings 506 as shown in
The weight of cutting unit 50 is preferably supported by the upper guide rod 200 and the siding movement of the cutting unit 50 is preferably controlled by the upper guide rod 200 sliding within the two slide bearings 506. The lower guide rod 200 preferably assists in guiding the cutting unit 50 as it slides along the guide rods 200 to prevent any rotational movement of the cutting unit 50 around the longitudinal axis 512 of the upper the guide rod 200.
The top guide rod 200 (as shown in
As can be seen in
Referring to
The two guide rods 200 of
While the embodiment of the present invention has been described with reference to a compound sliding miter saw, it will be appreciated that the invention is applicable to any saw having a cutting unit slideably mounted on a base assembly which is capable of making sliding cuts.
Number | Date | Country | Kind |
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1520416.7 | Nov 2015 | GB | national |
1520422.5 | Nov 2015 | GB | national |
1520423.3 | Nov 2015 | GB | national |